There can be an issue with clag in the waveguide, I understand from friends
who do work on these items. That leads to increased cooking times due to a
reduction in microwave power reaching the cooking cavity. I suppose cleaning
out the microwave path, and checking that the fans are running smoothly and
are not obstructed, and checking that the door switches are securely fixed,
and that the door and cabinet seals are all intact and not leaking, is what
would constitute " sevicing ". Otherwise, I agree that there's not a lot
that can be serviced in the traditional sense.

There can be an issue with clag in the waveguide, I understand from
friends who do work on these items. That leads to increased cooking times
due to a reduction in microwave power reaching the cooking cavity. I
suppose cleaning out the microwave path, and checking that the fans are
running smoothly and are not obstructed, and checking that the door
switches are securely fixed, and that the door and cabinet seals are all
intact and not leaking, is what would constitute " sevicing ". Otherwise,
I agree that there's not a lot that can be serviced in the traditional
sense.

Arfa

Click to expand...

Good points but IME obstructions in the wave guide generally cause failure
if not cleared immediately, and this only happens if the mica/plastic window
has been removed because of arcing, whenever people have brought ovens to me
in this condition I point out the temporary bodge of removing the mica
should have been taken as notice to start thinking about buying a new one.

It should be easy to hear if the fan is running and doesn't require a genius
level to clean the grating if that's what's needed, door switches OTOH are
not trivial although faults usually manifest themselves in an obvious way -
like blowing the fuse as the door is shut. Door seals are easy to check with
commercially available microwave leakage meters which are not at all
expensive, actually the most common cause of leakage is dirty seals - a
service is only a temporary fix for this if the owner doesn't clean it
(usually the engineer has earned his fee just cleaning it in this case!).

Getting back to what the OP really wanted, its worth being forewarned to
check before ordering which of the 2 sizes of ES thread sizes in common use,
also 220V microwave ovens sometimes have 2 110V lamps in series - they
should be replaced as a pair.

When does a microwave oven require a service - and what can be
serviced anyway?

Click to expand...

Never.

Not much.

These things are VERY dangerous and you should only try a repair if you have
enough brains to avoid being killed by them.

To quote an earlier message

WARNING: Microwave ovens are the most dangerous consumer appliance to
service due to the up to 5,000 V at high current inside. Even with the
power off, there is a HV capacitor that can produce quite a kick. This
capacitor must be discharged before touching anything in the microwave
generator circuitry.

Don't even think about tackling it yourself unless you have the appropriate
background and have thoroughly studied the Microwave Repair FAQ at the site
below as well as the info at: http://www.gallawa.com/microtech/, or a book
on
microwave oven repair. There is one by Homer L. Davidson that may be
available at your public library.

These things are VERY dangerous and you should only try a repair if you have
enough brains to avoid being killed by them.

To quote an earlier message

WARNING: Microwave ovens are the most dangerous consumer appliance to
service due to the up to 5,000 V at high current inside. Even with the
power off, there is a HV capacitor that can produce quite a kick. This
capacitor must be discharged before touching anything in the microwave
generator circuitry.

Don't even think about tackling it yourself unless you have the appropriate
background and have thoroughly studied the Microwave Repair FAQ at the site
below as well as the info at:http://www.gallawa.com/microtech/, or a book
on
microwave oven repair. There is one by Homer L. Davidson that may be
available at your public library.

Especially the SAFETY warnings and guidelines.

Click to expand...

Thanks to everyone for their useful responses, from which I can assume
that a service isn't required, and that it would be ok to unscrew the
casing (having unplugged first) and replace the bulb (having ensured
the correct size) myself - as long as I don't touch or fiddle with the
circuitry. If I can clean the fan filter so much the better.
Please let me know if I've misread the situation, but other than that
thank you all again. What a useful group!

Thanks to everyone for their useful responses, from which I can assume
that a service isn't required, and that it would be ok to unscrew the
casing (having unplugged first) and replace the bulb (having ensured
the correct size) myself - as long as I don't touch or fiddle with the
circuitry. If I can clean the fan filter so much the better.
Please let me know if I've misread the situation, but other than that
thank you all again. What a useful group!

Click to expand...

That's about it. There's a big 'can' with two terminals in there. It will
kill you if you touch it and are unlucky. Otherwise you should be fine.

There can be an issue with clag in the waveguide, I understand from friends
who do work on these items. That leads to increased cooking times due to a
reduction in microwave power reaching the cooking cavity. I suppose cleaning
out the microwave path, and checking that the fans are running smoothly and
are not obstructed, and checking that the door switches are securely fixed,
and that the door and cabinet seals are all intact and not leaking, is what
would constitute " sevicing ". Otherwise, I agree that there's not a lot
that can be serviced in the traditional sense.

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

When does a microwave oven require a service - and what can be
serviced anyway?

Click to expand...

When the bulb burns out.

In all sincerity, microwave ovens are very reliable pieces of equipment. It
is not uncommon for one to go 20 or more years with no reduction in
performance. Things that might require service include the moving parts,
such as the fan or turntable (if equipped) motor/drive system. Since there
is a fan inside most ovens, it stands to reason that dust will be pulled
inside the oven. This should be periodically cleaned out. Grease from things
such as bacon will eventually plug air passageways in the oven, but this too
can be cleaned up.

Other things can go wrong--the relay or triac on the controller board could
fail, units with mechanical timers could have the motor or gear train jam or
fail, and the magnetron can go weak or bad. These are all relatively
unlikely to happen.

Replacing the bulb is unlikely to be terribly difficult. Some ovens have an
access door for the bulb. (I have a small GE microwave oven from 1986 that
has a door on the side that can be unscrewed.) Others may make you take the
top cover off to get at the bulb. (I have a 1985 model large Sears Kenmore
(Sanyo) oven that is like this. It uses a strange type of bulb with a
"permanently" fastened socket. I was able to get a new bulb, but haven't put
it in yet.)

The Kenmore microwave recently had its internal fuse die of old age.
Replacing it with a new fuse fixed it, so maybe I'll replace the bulb while
I'm in there.

(Sanyo) oven that is like this. It uses a strange type of bulb with a
"permanently" fastened socket. I

Click to expand...

<snip>

Back in the days when I used to repair a lot of microwave ovens I
encountered these "funny" lamps from time to time, they were somewhat more
expensive than the normal ES types so holders were transplanted from a scrap
oven so normal bulbs could be used.

Guest

Back in the days when I used to repair a lot of microwave ovens I
encountered these "funny" lamps from time to time, they were somewhat more
expensive than the normal ES types so holders were transplanted from a scrap
oven so normal bulbs could be used.

Click to expand...

Better IME is to put a standard SES socket in, as non-nuke bulbs are
cheaper and work fine. The exception to this is with combis, where
tablelamp bulbs arent really upto spec.

Guest

The Kenmore microwave recently had its internal fuse die of old age.
Replacing it with a new fuse fixed it, so maybe I'll replace the bulb while
I'm in there.

William

Click to expand...

fuses of the sort of current ratings used in nukes dont usually die of
old age. Its possible it died due to an interlock fault that burnt the
interlock switch or shorting resistor out, leaving you with a now
dangerous nuke. When the main fuses pops you need to check the
microswitches and shorting resistor. Hopefully you already did.

fuses of the sort of current ratings used in nukes dont usually die of
old age. Its possible it died due to an interlock fault that burnt the
interlock switch or shorting resistor out, leaving you with a now
dangerous nuke. When the main fuses pops you need to check the
microswitches and shorting resistor. Hopefully you already did.

NT

Click to expand...

Microwaves are the one appliance I've had blow fuses occasionally for no
apparent reason. The one my parents had in the early 80s blew the fuse
when it was about 10 years old, replaced the fuse with a new one of the
same rating and it ran fine for another decade before it was replaced
for cosmetic reasons.

Want to reply to this thread or ask your own question?You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.